The Prince Of Arragon

The silver casket is said to bring the chooser 'as much as he deserves', which turns out to be The Portrait of a Blinking Idiot.
The schedule reads (extract)
"Take what wife you will to bed,
I will ever be your head:
So be gone: you are sped.
Still more fool I shall appear
By the time I linger here
With one fool's head I came to woo,
But I go away with two."